Examples of prior art in the field are given by U.S. Pat. No. 603,058 to H. Eldridge; U.S. Pat. No. 5,159,900 to W. A. Dammann et al; U.S. Pat. No. 5,435,274 to W. H. Richardson, Jr.; U.S. Pat. No. 5,417,817 to W. A. Dammann et al; U.S. Pat. No. 5,692,459 to W. H. Richardson, Jr.; U.S. Pat. No. 5,792,325 to W. H. Richardson, Jr. U.S. Pat. Nos. 6,926,872, 6,673,322, 6,663,752, 6,540,966, and 6,183,604, all issued to Rugerro Maria Santilli describe other approaches to these problems and other problems.
Submerged electric arcs were discovered over 150 years ago by sailors soon after the first constructions of metal ships. The combustible character of the gas produced by submerged electric arcs was discovered at the same time by sailors assisting the submerged operators; the ignored bubbles of gas reaching the water surface being referred by reports of the time as “fire on water.” Consequently, both submerged electric arcs and the combustible nature of the gas they produce are well known.
About one century ago attempts were initiated for the industrial production of the combustible gas produced by submerged electric arcs. Despite numerous efforts, no industrial and/or consumer utility emerged because the production of the combustible gas resulted to be very inefficient, thus excessively expensive, and suffered from serious environmental problems.
The efficiency in the art herein considered is generally given by the numerical value of the volume or calorific heat of the gas produced divided by the electric energy used for its production. The efficiency of conventional submerged electric arc is very low for several reasons. To begin, the electric arc is indeed very efficient for the separation of water molecules into hydrogen and oxygen atoms. Further reducing the efficiency is the latter recombination of the hydrogen and oxygen into water when the hydrogen and oxygen are contained in a plasma traversed by the electric arc combusting the hydrogen in an oxygen rich environment. In fact, the primary origin of the majestic glow of submerged electric arcs is not given by the arc itself, but rather by the recombination of hydrogen and oxygen into water. Additional reasons for the inefficiency of conventional submerged electric arcs are given by the loss of power caused by the electric resistance of carbon electrodes, particularly when in the dimension needed for a sufficient operational life.
In more recent decades the industrial production of a combustible gas via submerged electric arcs was considered again, but an additional problem emerged, this time of environmental nature. As it is well known, one of the biggest environmental problems afflicting our planet is the “global warming” caused by a disproportionate increase of carbon dioxide, CO2, in our atmosphere; estimated to be of the order of one million tons of CO2 per day as a result of the daily operation of an estimated number of about one billion cars, one million trucks, one hundred thousand planes, plus an unknown number of agricultural, industrial and military vehicles.
The serious environmental problem here considered is that the arc first creates around the tips of the electrodes a plasma composed by mostly ionized atoms of hydrogen, oxygen and carbon. The great affinity of carbon and oxygen then creates carbon monoxide, CO, with the release of heat. The residual hydrogen recombines into the hydrogen molecule H2 with the release of additional heat.
However, CO is combustible and, when in an oxygen rich plasma traversed by the electric arc, CO is turned into CO2 by providing a third source of heat. Consequently, the combustible gas produced by underwater electric arcs between carbon electrodes is generally composed by H2, CO, CO2, H2O and other gases. The alarming environmental problem here considered is that up to 25% of CO2 has been measured in the exhaust of said combustible gas, compared to about 5%-7% CO2 emission for gasoline operated cars. Hence, a widespread automotive and other uses of the resulting combustible gas releases a substantial amount of CO2 in the combustion exhaust.
Many of the above problems were resolved by U.S. Pat. No. 6,450,966 to Rugerro Maria Santilli, “Apparatus and Method for Recycling Contaminated Liquids”, discloses a continuous flowing of the liquid (feedstock) though the electric arc. Such a flow prevents much of the separated hydrogen and oxygen from recombining into water, thus permitting a dramatic increase of the efficiency on the order of about ten times that of stationary electric arcs therefore achieving sufficient efficiency for industrial and consumer utility. Additionally, the methods and apparatus also removes the various combinations of carbon and oxygen in single, double and triple valence bonds immediately following their creation, greatly reducing percentages of CO2 in the gaseous fuel produced.
The combustible gas produced by the process of '966 is currently produced and sold commercially. Such gas is clean because it generally contains no hydrocarbons due to the extreme temperature at which the gas is produced. Also, CO is a minor component of the combustible gas, rather than a byproduct of the combustion as is the case for fossil fuels. Hence, the presence of CO in an exhaust of a combustion engine using the produced gas is similar to the presence of gasoline in the exhaust of a gasoline fueled combustion engine, thus denoting in both cases incomplete or improper combustion. Additionally single bond C—O and double bond C═O contained in the gas are unstable and decompose under the combustion temperature releasing breathable oxygen in the exhaust. In fact, numerous measurements have established that, under full combustion, the combustion exhaust of the gas has no appreciable hydrocarbons or toxic substances such as carbon monoxide, CO, or nitrogen oxides, NOx, while being essentially comprised of 50%-55% water vapor, 12%-14% oxygen, 5%-7% carbon dioxide the rest being other atmospheric gases.
The '966 process resolved the basic problems of submerged stationary electric arcs but a need exists to achieve sufficient operating life of the consumable carbon electrodes prior to their replacement, as well so as to achieve a competitive cost for the gaseous fuel produced by this process making it attractive for industrial and consumer utility.
U.S. Pat. No. 6,926,872 addresses the issue of operating life using a number of configurations of durable carbon-base electrodes. A main problem in the production of clean burning gases from a submerged electric arcs is that it is not possible to use tungsten electrodes since they would melt almost instantly under 50 KW or higher power even when having substantial outer dimensions. Being such, carbon-base electrodes are the only electrodes known that are capable of withstanding the very high temperature of the submerged electric arc that reaches around 10,000 degrees Fahrenheit when powered with 100 KW.
Carbon-base electrodes are rapidly consumed, both in the delivery of high electric currents, and by consumption that is necessary to provide the carbon needed for the stability of the produced gaseous fuel. For instance, a DC electric arc between 1″ diameter carbon-base rod electrodes within water or water soluble liquid (feedstock) that is powered by a 50 KW DC generator generally consumes the positively charged cathode at the rate of about 1 linear inch per minute, corresponding to the consumption of about 0.76 cubic inches of carbon per minute or about 47 cubic inches of carbon per hour. A 50 KWH system generally produce 500 standard cubic feet (SCF) (cubic feet at atmospheric pressure) of combustible gas per hour, the consumption of carbon per cubic foot of the produced gas is in the order of 0.1 cubic inch of carbon per standard cubic foot of gas produced. The above consumption is dramatically reduced when the liquid (feedstock) is rich in carbon, such as oils or oil wastes. In all cases, the consumption of the negatively charged anode is generally minimal at around less the one tenth of the consumption of the cathode.
The problem of a durable configuration of the carbon electrodes has been addressed by U.S. Pat. No. 603,058 to H. Eldridge; U.S. Pat. No. 5,159,900 to W. A. Dammann et al; U.S. Pat. No. 5,435,274 to W. H. Richardson, Jr.; U.S. Pat. No. 5,417,817 to W. A. Dammann et al; U.S. Pat. No. 5,692,459 to W. H. Richardson, Jr.; U.S. Pat. No. 5,792,325 to W. H. Richardson, Jr. Nevertheless, all these configurations are afflicted by one or another of the following insufficiencies:
1) Inability of delivering high power to the electrodes (e.g. on the order of 500 KW or more). This limitation is addressed somewhat in the prior art using the copper rods to deliver power to electrodes that rotate to achieve a longer life. In some systems, the rotation forces the delivering of power via sliding contacts that, as such, have notorious limitation in power delivery due to micro arcs, abrasion, and other problems.
2) Inability to effectively enclose the incandescent area surrounding the electric arc. This inability is not addressed in the prior art due to structural differences between the anode and cathode. This limitation carries severe shortcomings in the utility of the invention. For instance, as discussed in U.S. Pat. No. 6,450,966, it is impossible to recycle city, farm or ship sewage with an electric arc unless the incandescent area is enclosed by suitable skirt. In absence of the skirt, there is always a portion of the sewage that is not exposed to the plasma of the electric arc and, therefore, such a system is incapable of fully sterilizing the liquid.
3) Inability to reach high pressure and temperature. In much of the prior art, copper rods that deliver the power to the electrodes passes through seals in order to penetrate inside the apparatus. In turn, such a configuration is inoperative at large pressure because the force of the pressure on the copper rods is so strong that it prevents the instantaneous micrometric motions necessary for the control of the electric arc. The same configurations often fail at high temperatures, such as those over 500 degrees F., due to the consequential failure of the seals. These limitations are rather serious because the efficiency of the apparatus increases dramatically with the increase of the operating pressure since the size of the bubbles of the gas surrounding the arc is reduced with pressure. This results in increasing of the travel of the arc through the liquid (feedstock). The efficiency of the apparatus also increases with the increase of the operating temperature because the arc first evaporates the liquid (feedstock), then separates the liquid molecules and then forms a plasma with their ionized atomic constituents. Consequently, operations at sufficiently high temperatures reduces the use of electric energy for evaporation with a consequential increase of the efficiency and reduction of costs.
U.S. patent application Ser. No. 11/474,687 filed on Jun. 26, 2007, by the inventor improves upon the prior art by disclosing an apparatus permitting: 1) the desired long electrode life of the order of weeks of continuous use prior to electrode replacement, 2) effective enclosure of the incandescent area of the electrodes to permit recycling of sewage (e.g. city, farm or ship) with sterilization; 3) delivery of very high electric power to the electrodes; 4) minimization of the power loss due to the minimal travel of the electric current through the electrodes despite the size of the electrodes; 5) production of the combustible gas at any desired pressure in order to eliminate the use for expensive compressed storage of the produced gas, for instance, to directly fill up an automotive tank; 6) achievement of high operating temperatures (e.g. of the order of 1,500 degrees F.) so as to permit the utilization of the heat produced by the apparatus for the production of steam via a heat exchanger that, in turn, can be used for the production of “green electricity,” (electricity meeting the environmental specifications according to the Kyoto Accord); and 7) automation in the extraction of the electrodes for easiness of service as well as complete automation of the operation and optimal use of the electrodes.
Despite these advances, a limitation exists of not entirely flowing the liquid through the gap of the electrodes, resulting in only part of the liquid being exposed to the incandescence of the electrode tips. This limits the efficiency, namely, the volume of liquid waste recycled for a given power input. This is evidently due to the fact that the produced combustible fuel exits rather violently from the gap between the electrodes, thus preventing the liquid (feedstock) from full flow-through penetration within the gap.
Furthermore, when the feedstock is subject to the plasma of the arc, the produced combustible fuel exits rather violently from the gap between the electrodes. Some of the combustible fuel ignites creating pressure waves.
What is needed is an apparatus and process that passes a liquid (feedstock) through a bore in one or both electrodes of an arc, while absorbing pressure waves created by combustion of some of the produced fuel, thus maximizing efficiency and utility.